Abstract-In distributed control system applications, there are many different functions should be realized on upper computer and lower computer respectively. It increased the amount of software development, software upgrades and maintenance become difficult. By studying the firmata protocol, the inverted C/S request mode is implemented in this paper. The upper computer possessed the control logic and the lower computer realized the concrete behaviors, and the upper computer send request to the lower computer. With the inverted C/S request mode, the lower computers realized with the same program, and the different behaviors of lower computers are controlled by upper computer. Meanwhile, we program on upper computer in efficient Python, and it will reduce time for developing, simplify software deployment and improve abilities of upgrade and maintenance.